Description And International CESSNA SKYMASTER 337 Operation AIRFRAME The Cessna Skymaster 337D and 337H are twin-engine, pusher and puller propellers, with direct-drive, air-cooled, horizontally opposed, fuel-injected, six- cylinder engine with 360 cu. in. displacement. Horsepower Rating and Engine Speed: 225 rated BHP at 2800 RPM. The Skymaster T337H-SP has a turbocharged engine and the cabin can be pressurized. The Cessna Skymaster is an innovative twin-engine civil utility aircraft built in a push-pull configuration. Instead of the engines being mounted on the wings, one is mounted on the nose and the other at the rear of the pod-style fuselage. The stabilizers are mounted on twin booms that extend from the wings. The rear engine is between the booms. With this "centerline thrust" configuration the aircraft si much easier to handle on one engine than a conventional configuration. The combination of a tractor and a pusher engine produces a unique unmistakable sound. Enthusiasts have no doubt when they hear a Skymaster fly over. Development The first model of the Skymaster was the 336. It had fixed landing gear and first flew in February 1961. It went into production in 1963 and 195 were produced to mid 1964. In 1965, Cessna introduced the model 337 Super Skymaster. This aircraft was larger, had more powerful engines, retractable landing gear and a dorsal air scoop for the rear engine (the "Super" was subsequently dropped from the name). In 1967 the turbocharged T377 was introduced and in 1972 the pressurized T377G entered production. Cessna built 1,859 standard and turbocharged Skymasters and 332 T337Gs. In addition, they built 513 military O-2 versions. Cessna production ended in 1980 but Skymaster production continued with Reims in France with the FTB337 STOL and the military FTMA Milirole. Reims produced a total of 94 Skymasters. After a 20-year hiatus the centerline thrust, pod and twin-boom concept has been revived in the Adam A500. Operational history The US Army used the O-2 variant as a Forward Air Controller platform during the Vietnam War. The California Division of Forestry uses the O-2 variant as spotter planes during firefighting operations. In 1994, the Cuban exile group Hermanos al Rescate (Brothers to the Rescue) used Skymasters to drop life-saving supplies to rafters attempting to cross the Florida Straits to defect from Cuba. They chose Skymasters because they were eaiser to control at slow speeds than conventional twin-engine aircraft. One plane contacted the water (it is difficult to judge altitude over relatively calm water), damaging the landing gear doors and the nose propeller. Since the rear engine is mounted higher, it wasn't damaged and the aircraft was able to return to Florida to make a belly landing. - 1 – For use with Microsoft Flight Simulator only. Not for use in real-world aviation! Copyright© 2005 by FSD International. All rights reserved. Description And International CESSNA SKYMASTER 337 Operation Variants Cessna 337 337A 337B 337M - US military version, designated O-2 Skymaster in service O-2A O-2B O-2T - turboprop-powered O-2 337C 337D 337E 337F 337G 337H T337B - turbocharged engines T337C T337D T337E T337F T337G T337H P337H T337H-SP Reims F337 F337 F337P - pressurized FTB337G - STOL version AVE Mizar Flying car created by Advanced Vehicle Engineers by attaching the wings, tail, and rear engine of a Skymaster to a Ford Pinto outfitted with aircraft controls and instruments. Summit Aviation built a militarized Skymaster as the O2-337 in 1980, and sold a few examples to the Haiti Air Corps and the Thai Air Force Spectrum Aircraft Corporation of Van Nuys, California made an extensive conversion of a Reims FTB337G in the mid 1980s - the Spectrum SA-550. They removed the nose engine, lengthened the nose and replaced the rear engine with a turboprop. This aircraft (serial number 61) is currently registered to Basler Turbo Conversions of Oshkosh, Wisconsin. Special Characteristics The Skymaster has different handling characteristics than a conventional twin- engine aircraft. Foremost is that it will not yaw into the dead engine if one engine quits. Consequently, it has no tendency to depart the runway if an engine fails on the takeoff roll. The adage, "dead foot, dead engine" -- used to remind a pilot which pro peller to feather when an engine quits -- is useless with the Skymaster. When a Skymaster loses power, the pilot must use the instruments to determine which engine has failed. The Skymaster is also controllable at lower airspeeds than - 2 – For use with Microsoft Flight Simulator only. Not for use in real-world aviation! Copyright© 2005 by FSD International. All rights reserved. Description And International CESSNA SKYMASTER 337 Operation a comparable conventional twin. There is no minimum controllable speed advisory (Vmc) on the airspeed indicator. Nevertheless, the Skymaster requires a multi-engine-rated pilot. The pilot must be trained to manage both engines, and must also be trained to handle the special characteristics of a multiengine aircraft with centerline thrust. One would think that with the Skymaster's superior single-engine handling it would have a lower accident rate than conventional twins. This turns out not to be true. The rear engine tends to overheat and quit while taxiing on very hot days. When this has happened, many pilots have inexplicably attempted take-off on the nose engine alone even though the single-engine take-off roll exceeded the runway length. The Skymaster also has a higher-than-average rate of accidents due to fuel mismanagement. This is puzzling since the fuel system is unremarkable. The Skymaster produces a unique unmistakable sound. All rear-engined aircraft produce a characteristic sound as the propeller slices through turbulent air coming off the airframe. Since the Skymaster also has a nose engine, with a propeller that operates in undisturbed air, its sound is different from a pure pusher. Ground Controller: Cessna calling ground control. Are you a Skymaster? Pilot's reply: No Sir. I'm just a student pilot. J Flight Controls The conventional primary flight controls are operated by dual control wheels and pedals. The control wheels operate the ailerons and the elevators. The adjustable pedals operate the rudder and the nose steering. The toe brakes, which are an integral part of the pedals, operate the wheel brakes. The pilot's and copilot's rudder pedals are individually adjustable. The control surfaces are mechanically connected to the pilot controls through systems of cables, pulleys, push-pull rods and bell-cranks. An up-down spring mechanism, linked to the stabilizer, is installed in the longitudinal control system to provide a suitable pilot stick force through the complete center of gravity range. The yaw trim is pilot-controlled through the RUDDER TRIM switch located on the pedestal trim control panel. The switch has three positions: NOSE LEFT, OFF and NOSE RIGHT. The switch knob is split and both halves must be rotated simultaneously to initiate yaw trim motion. When the switch is released, both halves return to the center OFF position. Actuation of the rudder trim switch to NOSE LEFT or NOSE RIGHT will signal the yaw trim actuator to move the rudder trim tab in the appropriate direction. FLIGHT CONTROLS The airplane's flight control system consists of conventional aileron, elevator and rudder control surfaces (see figure 7-1). The control surfaces are manually operated through mechanical linkage using a control wheel for the ailerons and elevator, and rudder/brake pedals for the rudders. - 3 – For use with Microsoft Flight Simulator only. Not for use in real-world aviation! Copyright© 2005 by FSD International. All rights reserved. Description And International CESSNA SKYMASTER 337 Operation TRIM SYSTEMS Manually-operated rudder and elevator trim is provided (see figure 71). Rudder trimming is accomplished through a bungee connected to the rudder control system and a trim control wheel mounted on the control pedestal. Rudder trimming is accomplished by rotating the horizontally mounted trim control wheel either left or right to the desired trim position. Rotating the trim wheel to the right will trim nose-right; conversely, rotating it to the left will trim nose-left. Elevator trimming is accomplished through the elevator trim tab by utilizing the vertically mounted trim control wheel next to the landing gear switch. Forward rotation of the trim wheel will trim nose-down; conversely, aft rotation will trim nose-up. The elevator trim tab system is also mechanically interconnected with the wing flap system to automatically eliminate excessive nose-up trim while retracting the wing flaps. The trim control wheel can be rotated forward to the NOSE DN position or aft to the lower half of the TAKEOFF range marking. The interconnect will prevent any additional nose-up trim with the flaps retracted. Flap extension will permit additional nose-up trim until the flaps are fully extended. At this point, maximum nose-up trim can be utilized. Any time flap extension is reduced with full nose-up trim, the interconnect will automatically reduce the trim setting. Full flap retraction will return the trim setting to the lower half of the TAKEOFF range marking. THIS SPACE LEFT INTENTIONALLY BLANK - 4 – For use with Microsoft Flight Simulator only. Not for use in real-world aviation! Copyright© 2005 by FSD International. All rights reserved. Description And International CESSNA SKYMASTER 337 Operation Figure 7.1 - 5 – For use with Microsoft Flight Simulator only. Not for use in real-world aviation! Copyright© 2005 by FSD International. All rights reserved. Description And International CESSNA SKYMASTER 337 Operation Figure 7.2 - 6 – For use with Microsoft Flight Simulator only. Not for use in real-world aviation! Copyright© 2005 by FSD International.